1. Field of the Invention
The present general inventive concept relates to a developing unit and an image forming apparatus having the developing unit.
2. Description of the Related Art
FIG. 1 is a view illustrating an example of a developing unit mounted in an image forming apparatus.
In FIG. 1, the developing unit includes a toner housing 2, a waste toner housing 6, and a photosensitive medium 5.
Toner is housed in the toner housing 2, and the toner is supplied to an electrostatic latent image on the photosensitive medium 5 by a supplying roller 3 and a developing roller 4.
The toner supplied to the electrostatic latent image is transferred onto a sheet of paper by a transferring unit, and waste toner that is not transferred onto the sheet of paper is removed by a cleaning member 7 mounted on the waste toner housing 6 and collected in the waste toner housing 6.
The toner housing 2 and waste toner housing 6 may be disposed at various positions. In order to reduce the volume of the developing unit, the toner housing 2 and waste toner housing 6 may be disposed respectively above and below a laser beam L of a laser scanning unit (not illustrated) when there is space between the toner housing 2 and waste toner housing 6 so that the laser beam L can pass, as illustrated in FIG. 1.
The interior of the waste toner housing 6 may be empty prior to accommodating waste toner, and wall surfaces of all areas except for an area on which the cleaning member 7 is mounted may be thermally bonded to each other.
However, an upper side of the waste toner housing 6 is formed in a thin plate shape, so vertical flow may occur. Such deformation of the waste toner housing 6 may frequently occur when distributing products or attaching and detaching the developing unit. If an upper surface of the waste toner housing 6 is deformed, the internal air pressure of the waste toner housing 6 may change and the housed waste toner may flow back out of the waste toner housing 6.
When the upper surface of the waste toner housing 6 is deformed, the positions of the cleaning member 7 and various film components for sealing which are mounted inside may be changed, which may cause the waste toner to undesirably flow back due to an air leak or insufficient cleaning.
Additionally, if the upper surface of the waste toner housing 6 is deformed by the heat inside the image forming apparatus, interference between a neighboring developing unit having a different color disposed on the upper side may occur in the case of a color image forming apparatus. It may be hard to attach or detach the developing unit due to interference between inner mounting components in the case of a mono-color image forming apparatus. These problems may be partially addressed by providing sufficient space between the toner housing 2 and the waste toner housing 6, but this undesirably increases the volume of the developing unit.